1. Field of the Invention
This invention relates to a sliding member of high strength and high abrasion resistance, and more particularly to a dense sliding member of high strength and high abrasion resistance having as a principal component thereof fine elongated silicon nitride particles.
2. Description of the Prior Art
In the conventional sliding members such as bearing materials destined to be used in zones of elevated temperatures, there are included sliding members which are formed of sintered silicon nitride.
These sliding members are such that their properties such as strength and abrasion resistance depend on the strength and abrasion resistance possessed by the sintered silicon nitride. The abrasion resistance is easily affected by the surface roughness of silicon nitride and the presence of pores therein. Thus, it has been difficult to obtain a sintered article of silicon nitride combining high strength and satisfactory abrasion resistance.
Particularly when a sliding member is used in a dry state, the conditions under which it is used are harsh. Thus, it has been very difficult to obtain a sliding member which can be used effectively under such working conditions.
The inventors continued a devoted study in search of means of enhancing the strength and abrasion resistance of a sliding member formed with sintered silicon nitride. They have consequently found that a sliding member combining high strength and high abrasion resistance is obtained when the fine silicon nitride particles present as a main component in the sintered article of elongated silicon nitride